MANAGEMENT OF NERVE INJURIES AND COMPRESSIVE NEUROPATHIES OF(2) copy.pptx

Reference: grabb & smith

1. MANAGEMENT OF NERVE INJURIES AND COMPRESSIVE NEUROPATHIES OF THE UPPER EXTREMITY Dr. Shahzad Shaikh , FCPS Plastic Surgery Dr. Sidra memon Plastic surgery resident

2. INTRODUCTION TO PERIPHERAL NERVE INJURY Axon - A basic subunit Endoneurium – covers myelinated and unmyelinated axons Perineurium – covers collection of axons that is fascicles Internal Epineurium – Groups together fascicles External epinerium – outermost layer, encases individual fascicular groups

3. ETIOLOGY PENETRATING TRAUMA TRACTION COMPRESSION ELECTRICAL INJURY THERMAL INJURIES

4. RESPONSE TO INJURY

5. SEDDON CLASSIFICATION OF NERVE INJURIES

6. NEUROPRAXIA Continuity not disrupted – conduction block Anatomy is intact – function is deteriorated – due to demyelination. Prognosis – good. Full recovery – within 2 – 3 months.

7. AXONOTMESIS Loss of continuity of the axons Architectural integrity Wallerian Degeneration Prognosis – favourable Axonal re-growth – 1 mm/day

8. NEUROTMESIS Complete nerve transection Disruption of all layers Functional as well as physical disruption Scarring within the intervening gap. Neuroma formation. Surgical approximation of stumps for recovery

9. SUNDERLAND’S CLASSIFICATION OF NERVE INJURIES

10. ELECTRO-DIAGNOSTIC STUDIES Two Components Nerve Conduction Test – Measures signal transmission Electromyograhy – Measures spontaneous and induced electrical activity

11. NERVE CONDUCTION TEST ELECTROMYOGRAPHY NEUROPRAXIA CONDUCTION BLOCK DECREASED VOLUNTARY MOTOR UNIT ACTION POTENTIAL, NO FIBRILLATION/ DENERVATION CHANGES DEVELOP AXONAL INJURY (AXONOTMESIS & NEUROTMESIS) CONDUCTION BOTH ABOVE & BELOW THE INJURY IS DISRUPTED FIBRILLATION & DENERVATION CHANGES IN AFFECTED MUSCLES 3 TO 4 WEEKS FOLLOWING INJURY

12. MANAGEMENT Depends on mechanism of injury and type of nerve injury. 1) Penetrating trauma– neurotmesis - Early surgical exploration (72 hours) recommended. 2) Closed injury – uncertain nerve continuity - observation Electro diagnostic studies conducted at 1 to 2 weeks to differentiate neuropraxic/axonal injuries & complete/incomplete lesions. Followed by repeat studies at 4 weeks. Differentiation of axonotmesis & neurotmesis – monitoring signs of recovery – return of motor unit potential confirms axonotmesis.

13. FACTORS GOVERNING TIMING OF INTERVENTION NEUROPRAXIC LESIONS – recovery within 8 to 12 weeks AXONOTMESIS - recovery within 3 to 6 months – repair at a rate of 1 mm/day IRREVERSIBLE INJURY – beyond 12 to 18 months (muscle atrophy occurs at a rate of 1 % per week) Surgical exploration needed – no recovery evident by 3 to 6 months

14. COMPRESSIVE NEUROPATHIES OF THE MEDIAN NERVE

15. CARPAL TUNNEL SYNDROME ANATOMY - fibro-osseous canal bounded by bony arch of carpus and transverse carpal ligament. CONTENTS - Median nerve, tendons of FDS, FDP, FPL - Median nerve runs in superficial & radial position Distally divided into sensory braches to digits and recurrent motor branch to thenar muscles. Palmar cutaneous nerve - 5cm proximal to wrist crease – superficial to TCL

16. ETIOLOGIC FACTORS Advanced age Female gender Obesity Diabetes Pregnancy Hypothyroidism Rheumatologic & autoimmune diseases Alcoholism Renal failure Space occupying lesions (proliferative tenosynovitis, hematoma, ganglion cysts etc ) Displaced distal radial or carpal injuries Occupational

17. HISTORY Paresthesias in radial digits Aggravated by prolonged wrist flexion/extension Relieved by shaking hand Nocturnal symptoms are hallmark of CTS Severe cases - constant symptoms Frequent dropping of objects Loss of cordination in hand.

18. EXAMINATION Decreased light touch sensation Semmer weinstein monofilament testing (most sensitive than two point discrimination) Atrophy of muscles in advanced disease Specific examination tests: Tinel’s Test, Phalen’s Test & Durkan’s test

19. ELECTRO DIAGNOSTIC STUDIES IN CTS NERVE CONDUCTION STUDIES Hallmark - increased distal latency and decreased conduction velocity Distal motor latency >4.5 ms – Diagnostic Distal sensory latency >3.5 ms – Diagnostic Decreased amplitude of distal potential – indicate axonal loss. ELECTROMYOGRAPHY Increased insertional activity, fibrillation and denervation potentials.

20. MANAGEMENT Based on duration and severity of symptoms, etiology and patient preference. Mild Cases: Non-surgical options (night splinting, corticosteroid injection) – less likely to benefit patients with prolonged symptoms or advance disease

21. SURGICAL OPTIONS Surgical release of the TCL – most effective 2 methods: Open or endoscopic OPEN METHOD 2 –4 cm incision at base of palm Palmar fascia & TCL incised longitudinally. Release is carried distally upto superficial arch. Proximally upto deep antebrachial fascia ENDOSCOPIC RELEASE Minimal scarring Less pain. Short recovery time Rapid return to work

22. PRONATOR SYNDROME A compressive neuropathy of the median nerve at the level of the elbow

23. EPIDEMIOLOGY more common in women common in 5th decade has been associated with well-developed forearm muscles (e.g. weight lifters)

24. PATHOANATOMY 5 potential sites of entrapment include  1) supracondylar process  residual osseous structure on distal humerus present in 1% of population 2) ligament of Struthers  travels from tip of supracondylar process to medial epicondyle  not to be confused with arcade of Struthers which is a site of ulnar compression neuropathy in cubital tunnel syndrome 3) bicipital aponeurosis (a.k.a. lacertus fibrosus)  4) between ulnar and humeral heads of pronator teres  5) FDS aponeurotic arch   

25. SYMPTOMS paresthesias in thumb, index, middle finger and radial half of ring finger as seen in carpal tunnel syndrome in pronator syndrome paresthesias often made worse with repetitive pronosupination should have characteristics differentiating from carpal tunnel syndrome (CTS)  aching pain over proximal volar forearm sensory disturbances over the distribution of palmar cutaneous branch of the median nerve (palm of hand) which arises 4 to 5 cm proximal to carpal tunnel   lack of night symptoms

26. PHYSICAL EXAM provocative tests are specific for different sites of entrapment positive Tinel sign in the proximal anterior forearm but no Tinel sign at wrist nor provocative symptoms with wrist flexion as would be seen in CTS resisted elbow flexion with forearm supination (compression at bicipital aponeurosis) resisted forearm pronation with elbow extended (compression at two heads of pronator teres) resisted contraction of FDS to middle finger (compression at FDS fibrous arch) possible coexisting medial epicondylitis

27. IMAGING Radiographs recommended views elbow films are mandatory  findings may see supracondylar process  STUDIES EMG and NCV may be helpful if positive but are usually inconclusive may exclude other sites of nerve compression or identify double-crush syndrome

28. NON-OPERATIVE rest, splinting, and NSAIDS for 3-6 months indications mild to moderate symptoms technique splint should avoid forearm rotation

29. OPERATIVE SURGICAL DECOMPRESSION OF MEDIAN NERVE   indications  only when non-operative management fails for 3-6 months technique decompression of the median nerve at all 5 possible sites of compression outcomes  of surgical decompression are variable 80% of patients having relief of symptoms

30. ANTERIOR INTEROSSEOUS NERVE SYNDROME A motor nerve Supplies FPL, FDP to the index &middle finger Pronator quadratus

31. SIGNS AND SYMPTOMS Weakness of FPL – difficulty in pinch Pain in anterior cubital fossa “OK” sign – difficulty in flexing IP joint of thumb and DIP of index finger when asked to make OK sign Middle finger DIP weakness less severe than index finger Pronator quadratus weakness when elbow is in flexed position

32. TREATMENT Most patient improve with conservative management within 3 – 6 months. Surgery – for persistent symptoms – curvilinear incision antecubital fossa and release from all potential sites of compression

33. COMPRESSIVE NEUROPATHIES OF THE ULNAR NERVE Ulnar nerve is terminal branch of the medial cord of the brachial plexus. 2nd most common compression neuropathy of the upper extremity. They occur at elbow and at wrist

34. ANATOMY Ulnar nerve pierces intra-muscular septum at arcade of Struthers 8 cm proximal to the medial epicondyle as it passes from the anterior to posterior compartment of the arm to enter cubital tunnel. Ulnar nerve then passes between two heads of FCU and runs distally between FCU and FDP muscle bellies.

35. COMMON SITES OF ENTRAPMENT Arcade of Struthers (most proximal) Medial Inter-muscular Septum Medical Epicondyle Osborne’s Ligament Cubital Tunnel (most common) Deep flexor-pronator aponeurosis (most distal) Anconeus epitrochlearis (anomalous muscle from the medial olecranon to the medial epicondyle) Aponeurosis of FDS proximal edge

36. External sources of compression 1) Fractures and medial epicondyle non-unions 2) Osteophytes 3) Heterotopic ossification 4) Tumors and ganglion cysts Associated conditions 1) Cubitus varus or valgus deformities 2) Medial epicondylitis 3) Burns 4) Elbow contracture release

37. CUBITAL TUNNEL SYNDROME Cubital tunnel Roof formed by FCU fascia and Osborne's ligament (travels from the medial epicondyle to the olecranon) Floor formed by posterior and transverse bands of MCL and elbow joint capsule Walls formed by medial epicondyle and olecranon

38. PRESENTATION SYMPTOMS Intermittent numbness & paresthesias of small finger, ulnar half of ring finger, and ulnar dorsal hand  exacerbating activities include  cell phone use (excessive flexion) occupational or athletic activities requiring repetitive elbow flexion and valgus stress Direct pressure poster-medial elbow. Night symptoms caused by sleeping with arm in flexion

39. PHYSICAL EXAM Inspection and palpation Interosseous and first web space atrophy  Ring and small finger clawing Observe ulnar nerve subluxation over the medial epicondyle as the elbow moves through a flexion-extension arc  Weakness of extrinsic muscles - FDP of small fingers FCU weakness is seldom encountered. Sensory Decreased sensation in ulnar 1-1/2 digits Loss over dorso -ulnar hand

40. MOTOR Motor loss of the ulnar nerve results in paralysis of intrinsic muscles (adductor pollicis , deep head FPB, interossei, and lumbricals 4 and 5) which leads to; Weakened grasp from loss of MP joint flexion power Weak pinch from loss of thumb adduction (as much as 70% of pinch strength is lost) Loss of dexterity Froment sign   Jeanne sign  Wartenberg sign Masse sign Extrinsic weakness Pollock's test shows weakness of two ulnar FDPs

41. Elbow examination Tenderness, Deformity, Crepitus or loss of motion Instability of nerve – subluxation or frank dislocation

42. PROVOCATIVE TESTS Provocative tests Tinel sign positive over cubital tunnel Elbow flexion test positive when flexion of the elbow for > 60 seconds reproduces symptoms Combined elbow flexion – compression test.

43. STUDIES EMG / NCV Helpful in establishing diagnosis and prognosis Threshold for diagnosis conduction velocity <50 m/sec across elbow low amplitudes of sensory nerve action potentials and compound muscle action potentials Fibrillation, denervation potential and increased insertional activity

44. TREATMENT NON-OPERATIVE NSAIDs, activity modification, and nighttime elbow extension splinting (within 6 to 12 weeks) Indications Mild symptoms Without objective muscle weakness Technique Night bracing in 45° extension with forearm in neutral rotation Avoid provocative activities Rest the elbow on firm surfaces. Outcomes management is effective in ~50% of cases

45. SURGICAL OPTIONS   IN SITU ULNAR NERVE DECOMPRESSION WITHOUT TRANSPOSITION   ULNAR NERVE DECOMPRESSION AND ANTERIOR TRANSPOSITION   MEDIAL EPICONDYLECTOMY

46. IN SITU ULNAR NERVE DECOMPRESSION WITHOUT TRANSPOSITION Indications Non-operative management fails Before motor denervation occurs Technique open release of osborne’s ligament endoscopically-assisted cubital tunnel release Limited dissection Preservation of surrounding vasculature. Outcomes meta-analyses have shown similar clinical results with significantly fewer complications compared to decompression with transposition RELATIVE CONTRAINDICATION Nerve instability Distorted tunnel anatomy

47. MEDIAL EPICONDYLECTOMY   Described as mini transposition Indications visible and symptomatic sub- luxating ulnar nerve Failure of medical treatment. Technique in situ release with medial epicondylectomy Outcomes risk of destabilizing the medial elbow by damaging the medial ulnar collateral ligament

48. ULNAR NERVE DECOMPRESSION AND ANTERIOR TRANSPOSITION  Addresses both direct compression and longitudinal traction  Indications Failed in situ release Throwing athlete Patient with poor ulnar nerve bed from tumor, osteophyte, or heterotopic bone Technique All potential sited of compression are released. Subcutaneous, sub-muscular, or intramuscular transposition relative to Flexor –pronator musculature. Advantage Results is decreased tension on nerve during elbow flexion Disadvantage extensive dissection and compromise of nerve’s blood supply

49. COMPLICATIONS Recurrence Secondary to inadequate decompression, perineural scarring, or tethering at the inter-muscular septum or FCU fascia higher rate of recurrence than after carpal tunnel release Neuroma formation Iatrogenic injury to a branch of the medial ante brachial cutaneous nerve may cause persistent posteromedial elbow pain

50. ULNAR TUNNEL SYNDROME ANATOMY Ulnar nerve and artery enters into ulnar tunnel ( guyon’s canal) BOUNDARIES Roof – volar carpal ligament Floor – TCL Medial border – Pisiform Lateral border – hook of hamate .

51. ZONES OF ULNAR TUNNEL ZONE I – proximal to bifurcation ZONE II – follows deep motor branch (at the level of fibrous arch oh hypothenar muscles & hook of hamate) ZONE III – follows suerficial sensory branch (courses along fascia of hypothenar muscles)

52. CAUSES DIRECT TRAUMA SPACE OCCUPYING LESIONS (GANGLION, ANOMALOUS MUSCLE BELLIES, BENIGN TUMORS) HYPOTHENAR HAMMER SYNDROME(REPETITIVE BLUNT TRAUMA) Direct nerve injury Hook of hamate fractures Thrombosis or pseudo-aneurysms of ulnar artery

53. PRESENTATION Depends on zone involved Zone I – both sensory and motor symptoms Zone II – motor symptoms (weak intrinsic muscles) Zone III – sensory (numbness and paresthesia of small and ring fingers, sparing the dorso ulnar hand)

54. EXAMINATION Hand examination similar to cubital tunnel syndrome Also asses tenderness over hook of hamate Abnormal allen’s test. Pulsatile mass over ulnar artery

55. INVESTIGATIONS ELECTRO-DIAGNOSTIC STUDIES Distinguish ulnar tunnel syndrome from proximal compression. IMAGING X-ray or CT scan – hook of hamate fracture MRI – soft tissue anomalies duplex ultrasound/angiography – thrombosis/pseudo-aneurysm

56. MANAGEMENT CONSERVATIVE Unidentifiable cause of compression Provocative activities avoided Wrist splints NSAID’s

57. SURGICAL INDICATION: Not responding to conservative management or space occupying lesion TECHNIQUE: Ulnar nerve and artery identified – proximal to wrist crease volar carpal – divided over neurovascular bundle to identify bifurcation of nerve motor branch – passes beneath proximal arcade of hypothenar muscles – arch is divided – floor around hook of hamate is examined Assesment for ulnar artery thrombosis / aneurysms – if present – ligation/graft reconstruction

58. COMPRESSIVE NEUROPATHIES OF RADIAL NERVE ANATOMY Terminal Branch – Brachial Plexus Medial to lateral – spiral groove of humerus Pierces lat : intramuscular septum – 10/12 cm proximal to lateral epicondyle Travels between brachialis and brachioradialis Elbow – anterior to radiocapitular joint Antecubital fossa – divides into PIN & Sup: radial sensory nerves

59. RSN – under brachioradialis muscle PIN – radial tunnel just distal to bifurcation – passes beneath fibrous edge of supinator -> post: compartment Multiple motor branches to extensor compartment as it exits radial tunnel

60. PIN COMPRESSION SYNDROME Radial tunnel – anatomic surroundings of PIN 5 potential sites of compression Fibrous bands – anterior to radiocapitular joint. Transversely crossing radial recurrent vessels (radial neck) Fibrous bands – ECRB Arcade of Frohse – leading edge of supinator (most common site – distal to leading edge of ECRB – formed by thickened aponeurotic band extending across proximal edge of superficial head of supinator) Distal fibrous edge of supinator

61. 2 syndromes – due to PIN compression at radial tunnel Radial Tunnel Syndrome PIN Syndrome

62. RADIAL NERVE SYNDROME Repetitive activity – pain in proximal and lateral forearm No motor/sensory loss. D/D – tennis elbow

63. PROVOCATIVE TESTS Pain with restricted forearm supination Pain with restricted middle finger MP joint extension

64. DIAGNOSIS Mainly clinical Electrodiagnostic studies – unrevealing Short acting local anesthtic in radial tunnel – useful test (relief of symptoms with PIN palsy – confirmatory)

65. MANAGEMENT CONSERVATIVE Splinting, stretching and NSAIDS Limiting provocative activities 3 months intervention before surgical options

66. SURGICAL Decompression – volar or dorsal approach All potential sites to be relieved Volar approach – uses brachioradialis & FCR interval (good for assesing proximal sites of compression) Dorsal approach – ECRL & ECRB interval or ECRL & brachioradialis interval (better acces to PIN)

67. POSTERIOR INTEROSSEOUS SYNDROME Motor nerve – extensor musculature Motor weakness Painless No sensory involvement

68. INVESTIGATION Electrodiagnostic studies – fibrillations and denervation potential Imaging – U/S or MRI – space occupying lesion

69. MANAGEMENT CONSERVATIVE If space occupying lesion is not suspected Intermittent extension splinting of MP joints For 3 months

70. SURGICAL If no recovery upto 3 months Technique – similar to that of RTS

71. WARTENBERG SYNDROME Compression of superficial radial nerve RSN – leaves cover of brachioradialis 9 cm above radial styloid Passes between ECRL and brachioradialis – enter subcutaneous plane. Most vulnerable – sharp radial border of brachioradialis tendon

72. Inciting factor – trauma (direct blow, handcuffs wrist bands, scarring) Painful dysthesia at dorsum of hand radiating to thumb, index and middle finger. Tinel sign – localizes site of compression. No motor loss – sensory nerve Spontaneous resolution - common Prolonged course on conservative management

73. Corticosteroid injection may be tried External compressing factors to be removed Refractory cases – surgical decompression – dividing fibrous dorsal margin of brachioradialis tendon